probability in javascript help?

Question

Sorry, I\'m new to JS and can\'t seem to figure this out: how would I do probability?

I have absolutely no idea, but I\'d like to do something: out of 100% chance, m

Answer 1

// generate cumulative distribution function from weights
function cdf(weights) {
    // calculate total
    var total = 0;
    for(var i=0; i cumul[i]); ++i) {};
    return i;
}

Code block to use the above

// setup (do this once)
var weights = [70,20,10];
var cumul = cdf(weights)

// get the index and pick the function
var ran = Math.random(); // 0 : 1
var func = funcs[selectInd(cumul,ran)]; 

// call the function
var someArgVal = 5;
var myResult = func(someArgVal);

// do it in one line
var myResult = (funcs[selectInd(cumul,Math.random())])(someArgVal);

Simplify calling code with a reusable object

function CumulDistributor(cumul,funcs) {
    var funcArr = funcs;
    var cumulArr = cumul;
    function execRandomFunc(someArg) {
        var func = funcArr[selectInd(cumulArr,Math.random())];
        return func(someArg);
    }
}

// example usage
var cdistor = new CumulDistributor(cumul,funcs);
var myResult = cdistor.execRandomFunc(someArgValue);